Inspection Procedure 2: Starter System


















OPERATION



  • The battery voltage is applied to the starter relay (terminal No. 4).
  • The battery voltage is applied to the starter relay (terminal No. 2) from the ETACS-ECU (terminal No. 15). The engine-ECU (terminal No. 26) makes the power transistor in the unit be in "ON" position and makes currents go on the starter relay coil, and that makes the relay be in "ON" position.
  • When the starter relay is in "ON" position, the battery voltage is supplied to the starter (terminal No. 1) from the starter relay (terminal No. 3).

FUNCTION



  • When the ignition switch ST signal is input to the engine-ECU, the engine-ECU places the starter relay in the ON position. Accordingly, the battery voltage is supplied to the starter.

PROBABLE CAUSES



  • Failed starter relay
  • Open/short circuit or harness damage in starter system circuit or loose connector contact.
  • Failed engine-ECU
  • Failed battery
  • Failed starter motor

DIAGNOSIS PROCEDURE


STEP 1. Check battery.



  • Check battery (Refer to GROUP 54A - Battery - On-vehicle Service - Battery test ).

Q. Is the check result normal?

Go to Step 2 .
Replace the battery.

STEP 2. Connector check: B-18 engine-ECU connector


Q. Is the check result normal?

Go to Step 3 .
Repair or replace the connector.

STEP 3. Perform voltage measurement at B-18 engine-ECU connector.



  • Disconnect connector, and measure at the harness side.
  • Ignition switch: ST
  • Voltage between terminal No. 31 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 9 .
Go to Step 4 .

STEP 4. Connector check: C-304 and C-315 ETACS-ECU connectors


Q. Are the check results normal?

Go to Step 5 .
Repair or replace the connector.

STEP 5. Continuity check on C-304 and C-315 ETACS-ECU connectors



  • Disconnect connectors, and measure at the ETACS-ECU side.
  • Continuity check between terminal No. 7 (C-315) and No. 15 (C-304)
OK: Continuity

Q. Is the check result normal?

Go to Step 6 .
Replace the ETACS-ECU.

STEP 6. Perform voltage measurement at C-315 ETACS-ECU connector.



  • Disconnect connector, and measure at ETACS-ECU side.
  • Ignition switch: ST
  • Voltage between terminal No. 7 and earth.
OK: System voltage

Q. Is the check result normal?


    Check and repair the harness between C-304 (terminal No. 15) ETACS-ECU connector and B-18 (terminal No. 31) engine-ECU connector.

    • Check power supply line for open/short circuit.
Go to Step 7 .

STEP 7. Connector check: C-210 ignition switch connector


Q. Is the check result normal?

Go to Step 8 .
Repair or replace the connector.

STEP 8. Check ignition switch.



  • Check ignition switch (Refer to GROUP 54A - Ignition Switch - Inspection ).

Q. Is the check result normal?


    Check and repair harness between C-315 (terminal No. 7) ETACS-ECU connector and C-210 (terminal No. 5) ignition switch connector.

    • Check power supply line for open/short circuit.
Replace the ignition switch.

STEP 9. Check harness between C-304 (terminal No. 15) ETACS-ECU connector and B-18 (terminal No. 31) engine-ECU connector.



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 10 .
Repair the damaged harness wire.

STEP 10. Check harness between C-210 (terminal No. 5) ignition switch connector and C-315 (terminal No. 7) ETACS-ECU connector.



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 11 .
Repair the damaged harness wire.

STEP 11. Connector check: A-27X starter relay connector


Q. Is the check result normal?

Go to Step 12 .
Repair or replace the connector.

STEP 12. Check starter relay.



  • Check starter relay (Refer to GROUP 16 - Starting System - On-vehicle Service - Starter Relay Check ).

Q. Is the check result normal?

Go to Step 13 .
Replace the starter relay.

STEP 13. Perform voltage measurement at A-27X starter relay connector.



  • Remove relay, and measure at the relay box side.
  • Voltage between terminal No. 4 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 14 .

    Check and repair harness between A-27X (terminal No. 4) starter relay connector and battery.

    • Check power supply line for open/short circuit.

STEP 14. Perform voltage measurement at A-27X starter relay connector.



  • Remove relay, and measure at the relay box side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 15 .

    Check and repair harness between A-27X (terminal No. 2) starter relay connector and C-304 (terminal No. 15) ETACS-ECU connector.

    • Check power supply line for open/short circuit.

STEP 15. Connector check: B-18 engine-ECU connector


Q. Is the check result normal?

Go to Step 16 .
Repair or replace the connector.

STEP 16. Perform voltage measurement at B-18 engine-ECU connector.



  • Measure engine-ECU terminal voltage.
  • Ignition switch: ON
  • Voltage between terminal No. 26 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 17 .

    Check and repair harness between A-27X (terminal No. 1) starter relay connector and B-18 (terminal No. 26) engine-ECU connector.

    • Check signal line for open/short circuit.

STEP 17. Connector check: B-09 starter connector.


Q. Is the check result normal?

Go to Step 18 .
Repair or replace the connector.

STEP 18. Perform voltage measurement at B-09 starter connector.



  • Disconnect connector, and measure at the harness side.
  • Ignition switch: ON
  • Using a jumper wire, connect B-18 (terminal No. 26) engine-ECU connector and earth.
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 22 .
Go to Step 19 .

STEP 19. Check harness between A-27X (terminal No. 3) starter relay connector and B-09 (terminal No. 1) starter connector.


note Before checking harness, check intermediate connector B-07, and repair if necessary.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?

Go to Step 20 .
Repair the damaged harness wire.

STEP 20. Check harness between C-304 (terminal No. 15) ETACS-ECU connector and A-27X (terminal No. 2) starter relay connector.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 21 .
Repair the damaged harness wire.

STEP 21. Check harness between A-27X (terminal No. 1) starter relay connector and B-18 (terminal No. 26) engine-ECU connector.



  • Check signal line for damage.

Q. Is the check result normal?

Replace the engine-ECU.
Repair the damaged harness wire.

STEP 22. Check harness between battery and A-27X (terminal No. 4) starter relay connector.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 23 .
Repair the damaged harness wire.

STEP 23. Check harness between A-27X (terminal No. 3) starter relay connector and B-09 (terminal No. 1) starter connector.


note Before checking harness, check intermediate connector B-07, and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 24 .
Repair the damaged harness wire.

STEP 24. Connector check: B-10 starter connector


Q. Is the check result normal?

Go to Step 25 .
Repair or replace the connector.

STEP 25. Perform voltage measurement at B-10 starter connector.



  • Disconnect connector, and measure at the harness side.
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 26 .

    Check and repair harness between B-10 (terminal No. 1) starter connector and battery.

    • Check power supply line for open/short circuit.

STEP 26. Check harness between B-10 (terminal No. 1) starter connector and battery.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 27 .
Repair the damaged harness wire.

STEP 27. Connector check: C-41 clutch switch connector


Q. Is the check result normal?

Go to Step 28 .
Repair or replace the connector.

STEP 28. Check clutch switch.



  • Check clutch switch (Refer to GROUP 21 - On-vehicle Service - Clutch Pedal Check And Adjustment ).

Q. Is the check result normal?

Go to Step 29 .
Replace the clutch switch.

STEP 29. Perform resistance measurement at C-41clutch switch connector.



  • Disconnect connector, and measure at the harness side.
  • Resistance between terminal No. 1 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 30 .

    Check and repair harness between C-41 (terminal No. 1) clutch switch connector and body earth.

    • Check earthing line for open circuit or damage.

STEP 30. Check harness between B-18 (terminal No. 14) engine-ECU connector and C-41(terminal No. 2) clutch switch connector.



  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Replace the starter.
Repair the damaged harness wire.